System and method for simultaneous measurement of turbidity and chlorine content of a sample of a liquid

ABSTRACT

A method for measuring turbidity and chlorine content of a liquid. The method includes shaking the liquid in a sample holder, using a shaker assembly, and removing bubbles including micro bubbles from the liquid using the micro-bubble removing shaker, retaining a sample volume of the liquid, and at least nearly simultaneously executing at least two of detecting illumination from the sample volume by a first detector operable for detecting illumination from the sample volume at a 90-degree angle with respect to an illumination beam generated by an illuminator and impinging on the sample volume, thereby measuring a turbidity of the sample volume, detecting illumination from the sample volume of liquid by a second detector operable for detecting illumination from the sample volume of liquid at a 180-degree angle with respect to the illumination beam, thereby measuring chlorine content of the sample.

REFERENCE TO RELATED APPLICATIONS

U.S. patent application Ser. No. 14/895,610, filed Jun. 2, 2014 andentitled “SYSTEM AND METHOD FOR SIMULTANEOUS MEASUREMENT OF TURBIDITY,COLOR AND CHLORINE CONTENT OF A SAMPLE OF A LIQUID”, is herebyincorporated by reference.

FIELD OF THE INVENTION

The present invention relates to water quality measurement, inparticular automated measurement of turbidity and/or color and/or freechlorine and/or total chlorine of liquids.

BACKGROUND OF THE INVENTION

Various types of equipment are known for measurement of turbidity, colorand chlorine content of liquids. However, existing equipment istypically not capable of simultaneously or near simultaneously measuringturbidity, color and chlorine content of a single sample of liquid,which would obviate the need to retrieve several samples of the liquidand analyze them separately.

SUMMARY OF THE INVENTION

The present invention relates to a system and method for simultaneous ornear simultaneous measurement of at least two of: turbidity, color andchlorine content of a sample of a liquid.

In accordance with embodiments of one aspect of the present inventionthere is provided a method for measuring turbidity, chlorine content andcolor of a liquid. The method includes retaining, from a continuous flowof the liquid, a sample volume of the liquid, and at least nearlysimultaneously executing at least two of (a) detecting illumination fromthe sample volume of liquid by at least a first detector operable fordetecting illumination from the sample volume of liquid at a 90-degreeangle with respect to an illumination beam generated by an illuminatorand impinging on the sample volume of liquid, thereby measuring aturbidity of the sample volume of liquid; (b) detecting illuminationfrom the sample volume of liquid by at least a second detector operablefor detecting illumination from the sample volume of liquid at a180-degree angle with respect to the illumination beam, therebymeasuring a color of the sample volume of liquid; and (c) detectingillumination from the sample volume of liquid by the at least seconddetector, thereby measuring a chlorine content of the sample volume ofliquid.

In some embodiments, the method also includes ascertaining that theilluminator operable to generate the illumination beam is functioningproperly. In some embodiments, the method also includes ascertainingthat the at least first detector and at least second detector arefunctioning properly. In some embodiments, the method also includesascertaining that a cleaning assembly of a holder of the volume ofliquid is functioning properly.

In some embodiments, the method also includes employing the cleaningassembly to clean the holder. In some embodiments, the method alsoincludes employing the cleaning assembly to remove air bubbles from thesample volume of liquid.

In some embodiments, ascertaining that the illuminator operable togenerate the illumination beam is functioning properly includesascertaining that the illuminator is provided with suitable electriccurrent.

In some embodiments, ascertaining that the at least first detector andthe at least second detector are functioning properly includes actuatingthe illuminator and analyzing outputs of the at least first detector andthe at least second detector to ascertain whether illumination generatedby the illuminator has been detected by both the at least first detectorand the at least second detector. In some embodiments, ascertaining thatthe at least first detector and the at least second detector arefunctioning properly also includes deactuating the illuminator andanalyzing outputs of the at least first detector and the at least seconddetector to ascertain whether illumination generated by the illuminatorhas been detected by either of the at least first detector and the atleast second detector.

In some embodiments, ascertaining that the cleaning assembly isfunctioning properly includes actuating the illuminator and ascertainingthat a shaker element forming part of the cleaning assembly isdisplaceable between at least a first position in which illuminationgenerated by the illuminator is detected by the at least seconddetector, and at least a second position in which the illumination beamimpinging on the sample volume of liquid is not detected by the at leastsecond detector.

In some embodiments, employing the cleaning assembly to clean the holderincludes retaining, from the continuous flow of the liquid, a cleaningvolume of the liquid in the holder, repeatedly displacing the shakerbetween the first position and second position for a first period oftime, releasing the cleaning volume of the liquid from the holder,retaining, from the continuous flow of the liquid, a test volume of theliquid in the holder, actuating the illuminator, and analyzing outputsof the at least first detector and the at least second detector toascertain whether illumination generated by the illuminator has beendetected by both the at least first detector and the at least seconddetector, and whether the illumination generated by the illuminator.

In some embodiments, employing the cleaning assembly to remove airbubbles from the sample volume of liquid includes repeatedly displacingthe shaker between the first position and second position for a secondperiod of time.

In some embodiments, detecting the illumination from the sample volumeof liquid by the at least the first detector, thereby measuring theturbidity of the sample volume of liquid, includes actuating theilluminator at a first current level, analyzing outputs of the at leastfirst detector and the at least second detector to ascertain whether theintensity of illumination generated by the illuminator at the firstcurrent level and detected by the at least first detector and the atleast second detector is within a predetermined range of intensity,responsive to ascertaining that the intensity of the illuminationgenerated by the illuminator at the first current level and detected bythe at least first detector and the at least second detector is withinthe predetermined range of intensity, a lookup table is employed todetermine the turbidity as a function of the intensity of theillumination at the first current level, responsive to ascertaining thatthe intensity of the illumination generated by the illuminator at thefirst current level and detected by the at least first detector and theat least second detector is not within the predetermined range ofintensity, actuating the illuminator at a second current which secondcurrent level is a function of the first current level, analyzingoutputs of the at least first detector and the at least second detectorto ascertain whether the intensity of illumination generated by theilluminator at the second current level and detected by the at leastfirst detector and the at least second detector is within thepredetermined range of intensity, and responsive to ascertaining thatthe intensity of the illumination generated by the illuminator at thesecond current level and detected by the at least first detector and theat least second detector is within the predetermined range of intensity,the lookup table is employed to determine the turbidity as a function ofthe intensity of the illumination at the second current level.Additionally, responsive to ascertaining that the intensity of theillumination generated by the illuminator at the second current leveland detected by the at least first detector and the at least seconddetector is not within the predetermined range of intensity, analyzingoutputs of at least one of a third detector and a fourth detector toascertain whether the intensity of illumination generated by theilluminator at either of the first current level and the second currentlevel and detected by the at least one of the third detector and thefourth detector is within the predetermined range of intensity, thethird detector being operable for detecting illumination from the samplevolume of liquid at a 45-degree angle with respect to the illuminationbeam and the fourth detector being operable for detecting illuminationfrom the sample volume of liquid at a 150-degree angle with respect tothe illumination beam, and responsive to ascertaining that the intensityof the illumination generated by the illuminator at either of the firstcurrent level and the second current level and detected by at least oneof the third detector and the fourth detector is within thepredetermined range of intensity, the lookup table is employed todetermine the turbidity as a function of the intensity of theillumination.

In some embodiments, the lookup table is based on a pre-calibrated lightintensity/turbidity curve for the first detector, and wherein turbidityvalues in the lookup table are based on nephelometric analysis.

In some embodiments, detecting the illumination from the sample volumeof liquid by the at least the second detector, thereby measuring thecolor of the sample volume of liquid, includes ascertaining whether theturbidity of the sample volume of liquid is within a predeterminedturbidity range, responsive to ascertaining that the turbidity of thesample volume of liquid is within the predetermined turbidity range,measuring the pH of the liquid, ascertaining whether the pH is within apredetermined pH range, responsive to ascertaining that the pH is notwithin the predetermined pH range, adjusting the pH of the sample volumeof liquid, measuring an adjusted pH of the sample volume of liquid andascertaining whether the adjusted pH is within the predetermined pHrange, responsive to ascertaining that the pH is within thepredetermined pH range, actuating the illuminator and obtaining anoutput of the at least second detector, and employing a color lookuptable and the output of the at least second detector to determineapparent color units and platinum cobalt true color units of the samplevolume of liquid.

In some embodiments, the predetermined pH range is between 4 and 10.

In some embodiments, adjusting the pH of the sample volume of liquidincludes employing at least one reagent pump to add at least one of anacid, a base or a buffer reagent to the sample volume of liquid and byemploying the shaker to mix the sample volume of liquid while removingbubbles therefrom.

In some embodiments, the lookup table includes apparent color unitsbetween 400 nm-700 nm and platinum cobalt true color units between450-465 nm as a function of turbidity range between 0 ntu-1000 ntu andpH between 4-10.

In some embodiments, detecting the illumination from the sample volumeof liquid by the at least second detector, thereby measuring thechlorine content of the sample volume of liquid, includes actuating theilluminator and obtaining a baseline output of the at least seconddetector, pumping a predetermined amount of a free chlorine indicatorand a free chlorine buffer solutions into sample volume of liquid andmixing the sample volume of liquid by employing the shaker, obtaining afirst test output of the at least second detector, and comparing thefirst test output to the baseline output to determine an amount of freechlorine in the volume of liquid.

In some embodiments, detecting the illumination from the sample volumeof liquid by the at least second detector, thereby measuring thechlorine content of the sample volume of liquid, also includes pumping apredetermined amount of a total chlorine indicator solution into samplevolume of liquid and mixing the sample volume of liquid by employing theshaker, obtaining a second test output of the at least second detector,and comparing the second test output to the baseline output to determinean amount of total chlorine in the volume of liquid.

In some embodiments, the free chlorine indicator is DPD 1. In someembodiments, the total chlorine indicator is DPD 3.

In some embodiments, detecting the illumination from the sample volumeof liquid by the at least second detector, thereby measuring thechlorine content of the sample volume of liquid includes actuating theilluminator and obtaining a baseline output of the at least seconddetector, pumping a predetermined amount of a total chlorine indicatorsolution into sample volume of liquid and mixing the sample volume ofliquid by employing the shaker, obtaining a test output of the at leastsecond detector, and comparing the test output to the baseline output todetermine an amount of total chlorine in the volume of liquid. In someembodiments, the total chlorine indicator is DPD 4.

There is also provided in accordance with another embodiment of thepresent invention a system for measuring turbidity, chlorine content andcolor of a liquid, the system including a sample holder operable forretaining, from a continuous flow of the liquid, a sample volume of theliquid, at least a first detector operable for detecting illuminationfrom the sample volume of liquid at a 90-degree angle with respect to anillumination beam generated by an illuminator and impinging on thesample volume of liquid, thereby measuring a turbidity of the samplevolume of liquid, and at least a second detector operable for detectingillumination from the sample volume of liquid at a 180-degree angle withrespect to the illumination beam, thereby measuring a color of thesample volume of liquid and thereby measuring a chlorine content of thesample volume of liquid.

In some embodiments, the system also includes illumination beamfunctionality ascertaining functionality operable for ascertaining thatthe illuminator is operable to properly generate the illumination beam.Preferably, the system also includes detector functionality ascertainingfunctionality operable for ascertaining that the at least first detectorand the at least second detector are functioning properly.

In some embodiments, the system also includes a holder cleaning assemblyoperable for cleaning the sample holder. In some embodiments, the systemalso includes holder cleaning assembly functionality ascertainingfunctionality operable for ascertaining that the cleaning assembly isfunctioning properly. In some embodiments, the holder cleaning assemblyis also operable for removing air bubbles from the sample volume ofliquid.

In some embodiments, ascertaining that the illuminator is operable toproperly generate the illumination beam includes ascertaining that theilluminator is provided with suitable electric current.

In some embodiments, ascertaining that the at least first detector andthe at least second detector are functioning properly includes actuatingthe illuminator, and analyzing outputs of the at least first detectorand the at least second detector to ascertain whether illuminationgenerated by the illuminator has been detected by both the at leastfirst detector and the at least second detector.

In some embodiments, ascertaining that the at least first detector andthe at least second detector are functioning properly also includesdeactuating the illuminator, and analyzing outputs of the at least firstdetector and the at least second detector to ascertain whetherillumination generated by the illuminator has been detected by either ofthe at least first detector and the at least second detector.

In some embodiments, the cleaning assembly includes a shaker. In someembodiments, ascertaining that the cleaning assembly is functioningproperly includes actuating the illuminator, and ascertaining that theshaker element forming part of the cleaning assembly is displaceablebetween at least a first position in which illumination generated by theilluminator is detected by the at least second detector, and at least asecond position in which the illumination beam impinging on the samplevolume of liquid is not detected by the at least second detector.

In some embodiments, employing the cleaning assembly to clean the holderincludes retaining, from the continuous flow of the liquid, a cleaningvolume of the liquid in the holder, repeatedly displacing the shakerbetween the first position and second position for a first period oftime, releasing the cleaning volume of the liquid from the holder,retaining, from the continuous flow of the liquid, a test volume of theliquid in the holder, actuating the illuminator, and analyzing outputsof the at least first detector and the at least second detector toascertain whether illumination generated by the illuminator has beendetected by both the at least first detector and the at least seconddetector, and whether the illumination generated by the illuminator.

In some embodiments, employing the cleaning assembly to remove airbubbles from the sample volume of liquid includes repeatedly displacingthe shaker between the first position and second position for a secondperiod of time.

In some embodiments, the system also includes at least a third detectoroperable for detecting illumination from the sample volume of liquid ata 45-degree angle with respect to the illumination beam and at least afourth detector operable for detecting illumination from the samplevolume of liquid at a 150-degree angle with respect to the illuminationbeam.

In some embodiments, measuring the turbidity of the sample volume ofliquid, includes actuating the illuminator at a first current level,analyzing outputs of the at least first detector and the at least seconddetector to ascertain whether the intensity of illumination generated bythe illuminator at the first current level and detected by the at leastfirst detector and the at least second detector is within apredetermined range of intensity, responsive to ascertaining that theintensity of the illumination generated by the illuminator at the firstcurrent level and detected by the at least first detector and the atleast second detector is within the predetermined range of intensity, alookup table is employed to determine the turbidity as a function of theintensity of the illumination at the first current level, responsive toascertaining that the intensity of the illumination generated by theilluminator at the first current level and detected by the at leastfirst detector and the at least second detector is not within thepredetermined range of intensity, actuating the illuminator at a secondcurrent which second current level is a function of the first currentlevel, analyzing outputs of the at least first detector and the at leastsecond detector to ascertain whether the intensity of illuminationgenerated by the illuminator at the second current level and detected bythe at least first detector and the at least second detector is withinthe predetermined range of intensity, and responsive to ascertainingthat the intensity of the illumination generated by the illuminator atthe second current level and detected by the at least first detector andthe at least second detector is within the predetermined range ofintensity, the lookup table is employed to determine the turbidity as afunction of the intensity of the illumination at the second currentlevel.

Additionally, responsive to ascertaining that the intensity of theillumination generated by the illuminator at the second current leveland detected by the at least first detector and the at least seconddetector is not within the predetermined range of intensity, analyzingoutputs of at least one of a third detector and a fourth detector toascertain whether the intensity of illumination generated by theilluminator at either of the first current level and the second currentlevel and detected by the at least one of the third detector and thefourth detector is within the predetermined range of intensity, thethird detector being operable for detecting illumination from the samplevolume of liquid at a 45-degree angle with respect to the illuminationbeam and the fourth detector being operable for detecting illuminationfrom the sample volume of liquid at a 150-degree angle with respect tothe illumination beam, and responsive to ascertaining that the intensityof the illumination generated by the illuminator at either of the firstcurrent level and the second current level and detected by at least oneof the third detector and the fourth detector is within thepredetermined range of intensity, the lookup table is employed todetermine the turbidity as a function of the intensity of theillumination.

In some embodiments, the lookup table is based on a pre-calibrated lightintensity/turbidity curve for the first detector, and wherein turbidityvalues in the lookup table are based on nephelometric analysis.

In some embodiments, measuring the color of the sample volume of liquid,includes ascertaining whether the turbidity of the sample volume ofliquid is within a predetermined turbidity range, responsive toascertaining that the turbidity of the sample volume of liquid is withinthe predetermined turbidity range, measuring the pH of the liquid,ascertaining whether the pH is within a predetermined pH range,responsive to ascertaining that the pH is not within the predeterminedpH range, adjusting the pH of the sample volume of liquid, measuring anadjusted pH of the sample volume of liquid and ascertaining whether theadjusted pH is within the predetermined pH range, responsive toascertaining that the pH is within the predetermined pH range, actuatingthe illuminator and obtaining an output of the at least second detector,and employing a color lookup table and the output of the at least seconddetector to determine apparent color units and platinum cobalt truecolor units of the sample volume of liquid.

In some embodiments, the predetermined pH range is between 4 and 10.Preferably, adjusting the pH of the sample volume of liquid includesemploying at least one reagent pump to add at least one of an acid, abase or a buffer reagent to the sample volume of liquid and by employingthe shaker to mix the sample volume of liquid while removing bubblestherefrom.

In some embodiments, the lookup table includes apparent color unitsbetween 400 nm-700 nm and platinum cobalt true color units between450-465 nm as a function of turbidity range between 0 ntu-1000 ntu andpH between 4-10.

In some embodiments, measuring the chlorine content of the sample volumeof liquid includes actuating the illuminator and obtaining a baselineoutput of the at least second detector, pumping a predetermined amountof a free chlorine indicator and a free chlorine buffer solutions intosample volume of liquid and mixing the sample volume of liquid byemploying the shaker, obtaining a first test output of the at leastsecond detector, and comparing the first test output to the baselineoutput to determine an amount of free chlorine in the volume of liquid.

In some embodiments, measuring the chlorine content of the sample volumeof liquid also includes pumping a predetermined amount of a totalchlorine indicator solution into sample volume of liquid and mixing thesample volume of liquid by employing the shaker, obtaining a second testoutput of the at least second detector, and comparing the second testoutput to the baseline output to determine an amount of total chlorinein the volume of liquid.

In some embodiments, the free chlorine indicator is DPD 1. In someembodiments, the total chlorine indicator is DPD 3.

In some embodiments, the measuring the chlorine content of the samplevolume of liquid includes actuating the illuminator and obtaining abaseline output of the at least second detector, pumping a predeterminedamount of a total chlorine indicator solution into sample volume ofliquid and mixing the sample volume of liquid by employing the shaker,obtaining a test output of the at least second detector, and comparingthe test output to the baseline output to determine an amount of totalchlorine in the volume of liquid. In some embodiments, the totalchlorine indicator is DPD 4.

According to some embodiments, a system is provided for measuringturbidity and chlorine content of a liquid. The system includes a sampleholder operable for retaining a sample volume of the liquid from acontinuous flow of the liquid; at least a first detector operable fordetecting illumination from the sample volume of liquid at a 90-degreeangle with respect to an illumination beam generated by an illuminatorand impinging on the sample volume of liquid, thereby measuringturbidity of the sample volume of liquid; at least a second detectoroperable for detecting illumination from the sample volume of liquid ata 180-degree angle with respect to the illumination beam, therebymeasuring a chlorine content of the sample volume of liquid; and ashaker configured to fit within the sample holder and configured tofacilitate cleaning thereof and/or bubble removal therefrom, within thesample holder.

According to some embodiments, a method is provided for measuringturbidity and chlorine content of a liquid. The method includes shakingthe liquid in a sample holder, using a shaker assembly, and removingbubbles including micro bubbles from the liquid using the micro-bubbleremoving shaker, retaining a sample volume of the liquid, and at leastnearly simultaneously executing at least two of detecting illuminationfrom the sample volume by a first detector operable for detectingillumination from the sample volume at a 90-degree angle with respect toan illumination beam generated by an illuminator and impinging on thesample volume, thereby measuring a turbidity of the sample volume,detecting illumination from the sample volume of liquid by a seconddetector operable for detecting illumination from the sample volume ofliquid at a 180-degree angle with respect to the illumination beam,thereby measuring chlorine content of the sample.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be understood and appreciated from thefollowing detailed description, taken in conjunction with the drawingsin which:

FIG. 1 is a simplified illustration of a color, turbidity and chlorinecontent (CTC) analysis system constructed and operative in accordancewith a preferred embodiment of the present invention;

FIGS. 2A and 2B are respective simplified assembled and exploded viewillustrations of a CTC measurement module employed in the system of FIG.1;

FIG. 3 is a simplified illustration of an illumination and detectionassembly, forming part of the CTC measurement module employed in thesystem of FIG. 1;

FIGS. 4A and 4B are simplified pictorial side view illustrations of abase element forming part of the illumination and detection assembly ofFIG. 3;

FIGS. 5A and 5B are simplified pictorial illustrations of a detectorassembly forming part of the illumination and detection assembly of FIG.3;

FIGS. 6A-6G are simplified flowcharts illustrating a preferred mode ofoperation of the system of FIGS. 1-5B; and

FIGS. 7A-7D show a shaker of the system in accordance with embodimentsthereof: FIG. 7A being a perspective view; FIG. 7B being a bottom view;FIG. 7C being a side view; and FIG. 7D being a cross-sectional viewalong section A-A of FIG. 7C.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 1 shows a simplified illustration of a color, turbidity andchlorine content (CTC) analysis system 100 constructed and operative inaccordance with a preferred embodiment of the present invention. System100 is preferably operable for simultaneously or nearly simultaneouslymeasuring turbidity, chlorine content and color of a liquid by: (a)retaining, from a continuous flow of the liquid, a sample volume of theliquid; and (b) at least nearly simultaneously executing at least twoof: (i) detecting illumination from the sample volume of liquid by atleast a first detector operable for detecting illumination from thesample volume of liquid at a 90-degree angle with respect to anillumination beam generated by an illuminator and impinging on thesample volume of liquid, thereby measuring a turbidity of the samplevolume of liquid; (ii) detecting illumination from the sample volume ofliquid by at least a second detector operable for detecting illuminationfrom the sample volume of liquid at a 180-degree angle with respect tothe illumination beam, thereby measuring a color of the sample volume ofliquid; and (iii) detecting illumination from the sample volume ofliquid by the at least second detector, thereby measuring a chlorinecontent of the sample volume of liquid.

As seen in FIG. 1, the CTC analysis system 100 includes a CTCmeasurement module 110 (see also FIGS. 2A and 2B), which is configuredto receive samples of liquid to be analyzed from a sampling cellassembly 120, via a solenoid valve 122. CTC measurement module 110 isalso configured to output liquid contained therewithin, such as analyzedsamples of liquid or liquid used for cleaning the interior of module110, via a drain pipe 124. Sampling cell assembly 120 may be, forexample, a sampling cell assembly commercially available from Blue-IWater Technologies Ltd. of Rosh Ha'ayin, Israel, under Catalog No.970-210-2120.

The operation of CTC measurement module 110 is preferably controlled bya computerized controller assembly 126, which is typically enclosed in aprotective enclosure 128. Enclosure 128 is typically separate from andadjacent to an enclosure 130, which enclosure 130 preferably houses CTCmeasurement module 110 together with part of sampling cell assembly 120,a multiplicity of reagent containers 132 and a multiplicity of reagentpumps 134. In addition to the specific operation of CTC measurementmodule 110 described hereinbelow, parts of the structure and operationof system 100 are described in U.S. Pat. No. 7,662,342 of the Applicant,the disclosure of which is hereby incorporated by reference.

FIGS. 2A and 2B are respective simplified assembled and exploded viewillustrations of CTC measurement module 110 employed in the system ofFIG. 1. In some embodiments, CTC measurement module 110 includes a baseelement 150 such as, for example, a base element commercially availablefrom Blue-I Water Technologies Ltd. of Rosh Ha'ayin, Israel, underCatalog No. 1-COVER-PCB. In some embodiments, housing element 160 ismounted onto base element 150. Housing element 160, may be, for example,a housing element commercially available from Blue-I Water TechnologiesLtd. of Rosh Ha'ayin, Israel, under Catalog No. 970-210-3004. In someembodiments, mounted onto base element 150 is a light-tight housingelement cover 170.

In some embodiments, disposed within a housing defined by base element150, housing element 160 and housing element cover 170 is a calibrationmemory board 180, which in some embodiments, includes a suitablyprogrammed EPROM, such as an 8 K I²C™ commercially available fromMicrochip Technology of Chandler, Arizona, USA under Catalog No.24AA08/24LC08B.

In some embodiments, disposed within the housing defined by base element150, housing element 160 and housing element cover 170 is an injectionmodule 190, such as an injection module commercially available fromBlue-I Water Technologies Ltd. of Rosh Ha'ayin, Israel, under eitherCatalog No. 970-210-3018 or Catalog No. 970-210-3019. In someembodiments, injection module 190 is supported upon a measuring head191, such as a measuring head commercially available from Blue-I WaterTechnologies Ltd. of Rosh Ha'ayin, Israel, under Catalog No.970-210-3014.

In some embodiments, injection module 190 is operable for injectingreagents into a sample of liquid which is held in a transparent glasssample holder 192, such as a glass sample holder commercially availablefrom Blue-I Water Technologies Ltd. of Rosh Ha'ayin, Israel, underCatalog No 970-210-3017.

In some embodiments, an illumination and detection assembly 200 isarranged to support sample holder 192 and to be in optical communicationtherewith, as described hereinbelow in detail with reference to FIGS.3-5B.

In some embodiments, associated with sample holder 192 is a sampleholder cleaning assembly 201 (FIG. 2B), such as a cleaning assemblycommercially available from Blue-I Water Technologies Ltd. of RoshHa'ayin, Israel, under Catalog Nos. 970-210-3101 and 970-210-3204.

FIG. 3 shows a simplified exploded view illustration of illumination anddetection assembly 200, and FIGS. 4A and 4B show simplified oppositeside view illustrations of a base element 202 thereof.

In some embodiments, as seen in FIGS. 3, 4A and 4B, illumination anddetection assembly 200 includes a base element 202, in some embodiments,preferably formed of plastic by injection molding. In some embodiments,base element 202 includes respective top and bottom plate portions 204and 206 which in some embodiments, are joined by a generally cylindricalportion 208. In some embodiments, an illumination conduit 210 intersectscylindrical portion 208. In some embodiments, an illuminator port 212 isformed at an end of illumination conduit 210.

In some embodiments, a bore 214 is formed through top plate portion 204,generally cylindrical portion 208 and bottom plate portion 206 of baseelement 202, along an axis 216 which is generally perpendicular to a topsurface of top plate portion 204. Bore 214 is configured to receivesample holder 192.

As seen particularly in FIG. 4A, generally cylindrical portion 208 isformed with multiple detector mounting ports arranged for light-tightmounting of light detector assemblies thereon. The detector mountingports preferably include a first detector mounting port 220 locatedperpendicular to an illumination axis 222 defined by illuminationconduit 210, and a second detector mounting port 224 located oppositeilluminator port 212 along illumination axis 222. Additional optionaldetector mounting ports 226 and 228 are preferably respectively arrangedat 45 and 150 degree angles relative to illumination axis 222.

As seen particularly in FIG. 4B, an illumination test detector port 230is preferably provided on illumination conduit 210, perpendicular toillumination axis 222.

Detector assemblies 240 are preferably removably mounted onto each ofdetector mounting ports 220, 224, 226, 228 and 230 in a light-tightmanner. An LED illuminator 250, such as a YZ-W5S20N LED lamp,commercially available from YolDal Ltd. of Zhonghe City Taiwan, ispreferably removably mounted onto illuminator port 212 of illuminationconduit 210. It is appreciated that illuminator 250 is preferablyconfigured for illuminating an interior volume of bore 214, therebyilluminating liquid contained within transparent glass sample holder192. Detector assemblies 240 are preferably operable for detectingillumination generated by illuminator 250 and which traverses liquidcontained within transparent glass sample holder 192.

Reference is now made to FIGS. 5A and 5B, which are simplified pictorialillustrations of detector assembly 240 forming part of illumination anddetection assembly 200 of FIG. 3. As shown in FIGS. 5A & 5B, detectorassembly 240 preferably includes a detector 260, such as a detectorcommercially available from Texas Advanced Optoelectronic Solutions Inc.of Plano, Tex., under either of catalog numbers TCS 3403 or TCS 3413,and a detector mount 262. Detector mount 262 preferably includes a portconnector portion 264, which is configured for tight engagement with anyof ports 220, 224, 226, 228 and 230 in a light-tight manner. Detectormount 262 preferably also includes a detector mounting portion 266,which is configured to retain detector 260 to port connector portion 264in a light-tight manner.

It is appreciated that detectors 260 are operative both as an ambientlight sensor and an RGB color sensor. It is also appreciated thatadditionally or alternatively, detectors 260 may be operative to detecta specific wavelength, or may be fitted with a filter operative tofilter only a specific wavelength.

Reference is now made to FIGS. 6A, 6B, 6C, 6D, 6E, 6F and 6G, which aresimplified flowcharts illustrating a preferred mode of operation ofsystem 100 of FIGS. 1-5B. As seen in FIG. 6A, the operation of system100 preferably includes the following principal steps:

ascertaining that illuminator 250 and detectors 240 are functioningproperly, as will be described in detail hereinbelow with reference toFIG. 6B (300);

ascertaining that sample holder cleaning assembly 201 is functioningproperly, as will be described in detail hereinbelow with reference toFIG. 6C (302);

employing sample holder cleaning assembly 201 to clean sample holder 192and to remove air bubbles from the liquid contained therein, as will bedescribed in detail hereinbelow with reference to FIG. 6D (304);

measuring the turbidity of liquid in sample holder 192, as will bedescribed in detail hereinbelow with reference to FIG. 6E (306);

measuring the color of the liquid in sample holder 192, the turbidity ofwhich was measured in step 306, as will be described in detailhereinbelow with reference to FIG. 6F (308); and/or

measuring free and/or total chlorine content of the liquid in sampleholder 192, the turbidity of which was measured in step 306, as will bedescribed in detail hereinbelow with reference to FIG. 6G (310).

Reference is now made to FIG. 6B, which describes step 300 (FIG. 6A),which includes ascertaining that illuminator 250 and detectors 240 arefunctioning properly.

As shown in step 320 of FIG. 6B, a flow of liquid is generallycontinuously provided into sample holder 192 from an opening at a bottomend thereof, and then flows out of sample holder 192 from an openingnear a top end thereof. As further shown in step 322, intermittently,and preferably periodically, an inlet valve governing the flow of liquidinto the sample holder 192 is closed and a precisely determined amountof liquid is retained in sample holder 192. The liquid is typicallydrinking water, however it may be any other liquid for which measuringof any of turbidity, color and chlorine content is desired.

As yet further shown in step 324, the system ascertains that illuminator250 is properly supplied with electric current. Responsive toascertaining that illuminator 250 is not properly supplied with electriccurrent, a suitable alarm is activated (326). Responsive to ascertainingthat illuminator 250 is properly supplied with electric current,illuminator 250 is actuated (328) and the outputs of detectors 260mounted on ports 220 and 224, arranged at 90 degrees and 180 degreesrespectively relative to illumination axis 222, are received andanalyzed to ascertain whether illumination has been detected (330).Failure to detect illumination at either one of detectors 260 mounted onports 220 and 224 causes a suitable alarm to be activated, noting atwhich of ports 220 and 224 illumination was not detected (332).

Alternatively or additionally, the output of detector 260 at port 230 isalso received and analyzed. Failure to detect illumination at thisdetector preferably also causes a suitable alarm to be activated.

If detectors 260 mounted on both ports 220 and 224 detect illumination,illuminator 250 is deactivated (334) and the outputs of detectors 260 atports 220 and 224 are again received and analyzed to ascertain whetherillumination has been detected, thereby ascertaining light tightness ofthe of the illumination and detection assembly of FIG. 3 (336). If lightis detected, a suitable alarm is actuated, noting at which of ports 220and 224 illumination was detected (338). If no light is detected, theprocess continues with step 302 of FIG. 6A (340).

FIG. 6C shows step 302 (FIG. 6A), which includes ascertaining thatsample holder cleaning assembly 201 is functioning properly.

As shown in FIG. 6C, illuminator 250 is initially activated (350). Whileilluminator 250 is activated, a shaker, forming part of sample holdercleaning assembly 201, is moved to an upward position at which it blockslight detection by detector 260 at port 224 (352). Detection of light atthis stage by detector 260 at port 224 (354) is an indication that theshaker did not move to the upward position and a suitable alarm isactuated (356).

If no light is detected at this stage by detector 260 at port 224, theshaker is then moved to a lower position at which it no longer blockslight detection by detector 260 at port 224 (358). No detection of lightat this stage by detector 260 at port 224 (360) is an indication thatthe shaker is stuck in the upward position and a suitable alarm isactuated (362). If light is detected at this stage by detector 260 atport 224, the process continues with step 304 of FIG. 6A (364).

FIG. 6D shows step 304 (FIG. 6A), which includes employing sample holdercleaning assembly 201 to clean sample holder 192 and to remove airbubbles from the liquid contained therein. Once sample holder 192 isfilled with a liquid sample (370), sample holder cleaning assembly 201is operated by using a shaker actuator to repeatedly move the shaker upand down for a time T1 (372). The liquid sample is then drained from thesample holder and a new liquid sample is retained in the sample holder(374).

Thereafter, illuminator 250 is actuated (376) and the outputs ofdetectors 260 mounted on ports 220 and 224, arranged at 90 degrees and180 degrees respectively relative to illumination axis 222, are receivedand analyzed to ascertain whether illumination has been detected (378).Failure to detect illumination at either of detectors 260 mounted onports 220 and 224, or detection of illumination at either of detectors260 mounted on ports 220 and 224 which is outside an expected range ofintensity, a suitable alarm is actuated indicating that the sampleholder 192 is dirty (380). If illumination detected at both detectors260 mounted on ports 220 and 224 is within the expected range ofintensity, sample holder 192 is refilled with a fresh liquid sample(382) and sample holder cleaning assembly 201 is operated to removebubbles from the liquid sample in the sample holder 192 by using theshaker actuator to repeatedly move the shaker up and down for a time T2(384).

FIG. 6E shows step 306 (FIG. 6A), which includes measuring the turbidityof liquid in sample holder 192. To measure the turbidity of the liquidin sample holder 192, the illuminator 250 is initially operated at apredetermined current, or at a current used in a preceding measurement(400). The outputs of detectors 260 mounted on ports 220 and 224arranged at 90 degrees and 180 degrees respectively relative toillumination axis 222 are received and analyzed to ascertain whether theillumination detected at detectors 260 mounted on ports 220 and 224 iswithin a predetermined range of intensity (402).

Responsive to ascertaining that the intensity of the illuminationdetected at detectors 260 at ports 220 and 224 is within a predeterminedrange of intensity, a lookup table is used to determine the turbidity asa function of the intensity of the illumination detected at detector 260mounted on port 220, arranged at 90 degrees relative to illuminationaxis 220 (404), and the turbidity value is provided as an output (406).The lookup table is preferably based on a pre-calibrated lightintensity/turbidity curve for detector 260 at port 220 arranged at 90degrees relative to illumination axis 220. It is appreciated that theturbidity values are based on nephelometric analysis.

Responsive to ascertaining that the intensity of the illuminationdetected at detectors 260 at ports 220 and 224 is not within thepredetermined range of intensity, the current level of illuminator 250is changed to a second current level (408), which second current levelis typically a function of the previous current level. Thereafter, theoutputs of detectors 260 mounted on ports 220 and 224 arranged at 90degrees and 180 degrees respectively relative to illumination axis 222are again received and analyzed to ascertain whether the illuminationdetected at detectors 260 mounted on ports 220 and 224 are within thepredetermined range of intensity (410). Responsive to ascertaining thatthe illumination detected at detectors 260 at ports 220 and 224 iswithin the predetermined range of intensity, a lookup table is used todetermine the turbidity as a function of the intensity of theillumination detected at detector 260 mounted on port 220, arranged at90 degrees relative to illumination axis 220 (404), and the turbidityvalue is provided as an output (406).

Responsive to ascertaining that the intensity of the illuminationdetected at detectors 260 mounted on ports 220 and 224 is still notwithin the predetermined range, a suitable alarm is actuated indicatingthat the turbidity value is out of range (412). Alternatively, theoutputs of detectors 260 at port 226 and/or 228, arranged at 45 degreesand 150 degrees respectively relative to illumination axis 222, arereceived and analyzed to ascertain whether the illumination detected atdetectors 260 mounted on port 226 and/or 228 is within a predeterminedrange (414). Responsive to ascertaining that the intensity of theillumination detected at detectors 260 mounted on ports 226 and/or 228is within the predetermined range, a lookup table is used to determinethe turbidity as a function of the illumination detected at detector 260mounted on port 226 or 228 (416). Responsive to ascertaining that theillumination detected at detectors 260 mounted on port 226 and/or 228are not within the predetermined range, a suitable alarm is actuatedindicating that the turbidity value is out of range (412).

FIG. 6F shows step 308 (FIG. 6A), which includes measuring the color ofthe liquid in sample holder 192, the turbidity of which was measured instep 306. It is appreciated that the color of a liquid typicallycorrelates with the level of contamination of the liquid. For example,drinking water may be colored as a result of contamination by materialdissolved in the liquid such as, for example, soil or pipe corrosion.

Initially, the system ascertains whether the turbidity of the liquid insample holder 192 measured as described in FIG. 6E was within thepredetermined range (420). Responsive to ascertaining that the turbiditywas not within the predetermined range, a suitable alarm is actuatedindicating that the color measurement is out of range due to highturbidity (422).

Responsive to ascertaining that the turbidity was within thepredetermined range, the pH of the liquid in sample holder 192 ismeasured (424) and the system ascertains whether the pH is within apredetermined range, typically a range of 4-10 (426). It is appreciatedthat the pH of the liquid may be measured before entering sample holder192.

Responsive to ascertaining that the pH is not within the predeterminedrange, the pH of the liquid sample in sample holder 192 is adjusted(428). The adjustment of the pH is to within the predetermined range,typically to a value of 7.0 or to any other suitable pH, by employingone of reagent pumps 134 to add one of an acid, base or buffer reagentto the sample and by employing the shaker to mix the liquid sample insample holder 192 while removing bubbles therefrom. Thereafter, a secondpH measurement is performed on the same liquid sample in sample holder192 to ascertain that the pH is within the predetermined range (426).

Responsive to ascertaining that the pH is within the predeterminedrange, a current is applied to illuminator 250 (430) and illumination ismeasured using the detector 260 at port 224, arranged at 180 degreesrelative to illumination axis 222 (432). A lookup table is thenemployed, together with the output of detector 260 at port 224, todetermine apparent color units and platinum cobalt true color units ofthe liquid sample in sample holder 192 (434).

In some embodiments, the lookup table includes apparent color units(400-700 nm) and platinum cobalt true color units (450-465 nm) as afunction of turbidity range (0-1000 ntu) and pH (4-10). The lookup tableis used to eliminate the influence of turbidity and pH on the detectionand determination of color of the liquid sample. Based on the lookuptable, computerized controller assembly 126 determines and outputs acolor value for each of apparent color and platinum cobalt color (436).

FIG. 6G shows step 310 (FIG. 6A), which includes measuring free and/ortotal chlorine content of the liquid in sample holder 192, the turbidityof which was measured in step 306. It is appreciated that the freechlorine content of a liquid typically correlates to the residualdisinfecting power of the liquid, and that the total chlorine content ofa liquid typically correlates to the overall level of contamination ofthe liquid.

As seen in FIG. 6G, illuminator 250 is activated (440), and illuminationis preferably detected at detector 260 mounted on port at port 224,arranged at 180 degrees relative to illumination axis 222 (442) toobtain a baseline measurement based on the color of the detectedillumination, which baseline measurement will be employed in asubsequent free chlorine measurement. The baseline measurement is usedfor compensating the subsequent free chlorine measurement for to accountfor turbid water, colored water and/or dirt in sample holder 192.

Thereafter, a predetermined amount of free chlorine indicator, such asDPD 1, and free chlorine buffer solutions are preferably pumped intosample holder 192 and are mixed with the liquid sample by employing theshaker (444). A chemical reaction between the free chlorine indicatorand any free chlorine in the liquid sample (hypochlorousacid+hypochlorite ions) typically induces a color change, typically froma clear color to red. If no free chlorine is present, no change in colorwill occur.

Thereafter, illumination is again detected at detector 260 mounted onport at port 224, arranged at 180 degrees relative to illumination axis222 (446), which detected illumination is then compared with thebaseline measurement obtained in step 442 to determine the amount offree chlorine (448). This value is typically reported in parts permillion (ppm) or mg/l.

In a case where total chlorine is to be measured as well, apredetermined amount of total chlorine indicator (DPD 3) is then pumpedinto sample holder 192 into the liquid sample which already contains thefree chlorine indicator and the free chlorine buffer (450). The shakeris then preferably employed to mix the sample (452). A chemical reactionbetween the total chlorine indicator and any total chlorine typicallyinduces a color change from clear to red to a new shade of red. If nototal chlorine is present no change in color will occur.

It is appreciated that in a case where it is desired to measure thetotal chlorine, without first measuring free chlorine, a total chlorineindicator such as DPD 4 is preferably used.

Thereafter, in some embodiments, illuminator 250 is activated once again(454) and illumination is preferably detected at detector 260 mounted onport at port 224, arranged at 180 degrees relative to illumination axis222 (456), to obtain a measurement of the total chlorine concentrationof the sample, based on the color of the detected illumination.

The inlet valve is then reopened to allow fresh water to flow throughsample holder 192 (458) and the shaker moves again to clean thecolorimeter and prepare for the next reading (460).

FIGS. 7A-7D show a shaker 500 of the system in accordance withembodiments thereof, which is configured to fit within sample holder 192of the sample holder cleaning assembly 201. Shaker 500, hereinafterreferred to as micro shaker, in some embodiments, has a generallycylindrical shape and includes an upper portion 502 and central waistportion 504 and a lower sample-holder cleaning portion 506, which inpreferred embodiments acts to wash the sample windows and to removebubbles from the liquid sample, and in particular micro bubbles. Withoutlimitation to theory, it is believed that the configuration of microshaker 500 facilitates removal of micro-bubbles, via the escape channels(e.g. upwardly angled side bubble-exit ports 516) of shaker 500 and/orthe glomming of micro-bubbles into larger bubbles, which escape throughescape channels. The removal of bubbles, including micro bubbles, from aliquid facilitates the turbidity analysis within the sample holder.Micro bubbles, as used herein, may refer to tiny or small bubbles,typically under the threshold size of bubbles that are traditionallyremoved by using typical cleaning assemblies.

As noted above, sample holder cleaning assembly 201 is operated by usinga shaker actuator to repeatedly move the shaker 500 up and down for atime T1 (372). In this regard, in some embodiments, cleaning assembly,and in particular shaker 500, includes a magnetic element (exemplifiedwithout limitation as magnetic element 501 disposed in lower portion506; FIG. 7B), which may be housed in or constituted by any of portions502, 504, or 506; but most typically disposed in upper portion 502 orcentral waist portion 504. In alternatively exemplary embodiments,sample holder cleaning assembly 201 includes or has associated therewitha mechanical shaking mechanism to move shaker 500 up and down withinsample holder 192.

Lower portion 506 of shaker 500 is configured to help clean and/or“debubble” the liquid sample, and optionally to mechanically holdmagnetic element 501 therein. Without limitation to theory, for saidpurpose, lower portion 506 has a combination of features, in which anyof such features can be designed and incorporated alone or incombination with each other. For instance, in some embodiments, outerwalls of lower portion include one or more fluted portions or flutes508. As best seen in FIGS. 7A and 7C, such flutes 508 may be generallyparallel to the longitude of the shaker 500 and be elongated or runalong only a portion of lower portion's outer wall, such as descendingpartially downward or ascending partially upward.

As best seen in FIGS. 7B and 7D, in some embodiments, lower portion 506of shaker 500 includes one or more internal baffles 510, which, again,without limitation to theory, either help mix and/or shake up the liquidsample, to help clean the sample holder and/or help remove bubbles, andin particular micro bubbles therefrom, as well as aid in holdingmagnetic element 501. As shown, in some embodiments, baffles 510 runvertically along an internal cavity 512 of lower portion 506. In someembodiments, baffles 510 are secured to the walls of the shaker's lowerportion 506 along their sides in a radial format (FIG. 7B). In someembodiments, as seen in FIG. 7B, baffles 510 are secured to avertically-oriented internal annular element 514 along their sides. Sucha design forms internal cavity 512 into a plurality of such cavities,which can be helpful for removing bubbles from the liquid sample,substantially within the sample holder.

Without limitation to theory, it is believed that the vertical tunnels(i.e. plurality of cavities 512 partially formed by baffles 510) helpdirect the path of bubbles, and in particular micro bubbles, in thesample upward. To further direct, and also facilitate exiting of suchbubbles, micro shaker 500 also includes at least one, and typically aplurality of, angled side bubble-exit ports 516 as part of a Y-shapedchannel.

In some embodiments, waist portion 504 is configured to snuggly or atleast closely fit within sample holder 192 in order to facilitate mixingand/or bubble removal of the liquid sample.

It will be appreciated by persons skilled in the art that the presentinvention is not limited to what has been particularly shown anddescribed hereinabove. Rather the scope of the invention includes bothcombinations and sub-combinations of the various features describedhereinabove as well as modifications and variations thereof which wouldoccur to persons skilled in the art upon reading the foregoingdescription and which are not in the prior art.

1. A system for measuring turbidity and chlorine content of a liquid,said system comprising: a sample holder operable for retaining, from acontinuous flow of said liquid, a sample volume of said liquid; at leastone first detector operable for detecting illumination from said samplevolume of liquid at a 90-degree angle with respect to an illuminationbeam generated by an illuminator and impinging on said sample volume ofliquid, thereby measuring a turbidity of said sample volume of liquid;at least one second detector operable for detecting illumination fromsaid sample volume of liquid at a 180-degree angle with respect to saidillumination beam, thereby measuring the chlorine content of said samplevolume of liquid and thereby measuring a chlorine content of said samplevolume of liquid; and a shaker configured to fit within said sampleholder and configured to facilitate cleaning thereof and/or micro bubbleremoval therefrom, said shaker configured with at least one of: (a) atleast one angled bubble port forming part of a Y-shaped channel; (b) alower portion comprising at least one internal baffle; and (c) a lowerportion with at least one fluted portions.
 2. The system of claim 1,wherein said shaker comprises an upper portion; a waist portion and alower portion.
 3. (canceled)
 4. (canceled)
 5. (canceled)
 6. The systemof claim 1, wherein said shaker comprises a waist portion configured tofit snuggly with the sample holder.
 7. The system of claim 1, whereinsaid shaker is configured to move up and down via a shaker actuator. 8.(canceled)
 9. The system of claim 1, wherein said at least one internalbaffle is a plurality of baffles.
 10. The system of claim 9, whereinsaid plurality of baffles at least partially define a plurality ofbubble-directing tunnels or cavities.
 11. The system of claim 1, whereinsaid at least one internal baffle is secured to a wall of a lowerportion of the shaker.
 12. The system of claim 9, wherein said at leastone internal baffle is secured to a vertically-oriented internal annularelement within a lower portion of the shaker.
 13. A method for measuringturbidity and chlorine content of a liquid, said method comprising:retaining, from a continuous flow of said liquid, a sample volume ofsaid liquid; shaking or mixing the sample volume of said liquid;removing micro bubbles from said liquid, using a shaker assembly, saidshaker assembly comprising a shaker configured with any one of: (a) atleast one angled bubble port forming part of a Y-shaped channel; (b) alower portion comprising at least one internal baffle; (c) a lowerportion with at least one fluted portion; detecting illumination fromsaid sample volume of liquid by at least one first detector operable fordetecting illumination from said sample volume of liquid therebymeasuring a turbidity of said sample volume of liquid; and detectingillumination from said sample volume of liquid by at least one seconddetector, thereby measuring a chlorine content of said sample volume ofliquid.
 14. The method of claim 13, wherein said first detector operatesat a 90-degree angle with respect to an illumination beam generated byan illuminator and impinging on said sample volume of liquid.
 15. Themethod of claim 13, wherein said second detector operates at a180-degree angle with respect to an illumination beam generated by anilluminator and impinging on said sample volume of liquid.
 16. Themethod of claim 13, wherein said shaking or mixing comprises moving ashaker up and down in said sample volume of said liquid.